1. Field of the Invention
The invention relates to a device for damping pressure pulsations, and a hydraulic unit equipped with this device, in an electronically regulatable vehicle brake system. For regulating the brake pressure required at the wheel brake cylinders, electronically regulatable vehicle brake systems require pump elements, which are acted upon as needed by a rotating drive element. This action is effected cyclically, and as a result, pressure pulsations can occur in the hydraulic circuit connected to it during the regulation cycle. The pressure pulsations can be transmitted to the brake pedal via the master cylinder located in the hydraulic circuit. The consequence is unwanted pulsating motions of this brake pedal as well as noise that is perceptible in the vehicle interior.
2. Description of the Prior Art
For damping the pressure pulsations in an electronically regulatable brake system, a device is already known from German Patent Disclosure DE 42 34 013 A1. FIG. 3 of this reference shows a hydraulic block of an electronically controllable vehicle brake system, with a receiving bore which forms the housing of the device. The receiving bore is closed off from its surroundings by a cap anchored by positive engagement, and in its interior it defines a damping chamber. An inflow conduit arriving from a pump element discharges into this chamber, and an outflow conduit emerges from it. At the exit point of the outflow conduit there is a throttle, along with a separate filter element preceding the throttle. The filter element prevents clogging of the throttle from an accumulation of dirt.
It is a disadvantage of the design of this known noise-damping device that the filter and the throttle are each individual components, which must be anchored to the hydraulic block in separate assembly steps. The individual components are of metal and are relatively complicated to produce, in multiple machining steps. Their reliable fixation must be checked and assured during assembly. This makes the known device comparatively expensive.